Experimental Data

Abstract

Only a few parameters of the double layer can usually be determined in experiment. First of all, it is the electrocapillary curve σ(ψm), that is dependent on surface tension of a (liquid) electrode σ on the potential ψm, and also the differential capacity curves Cm-s(ψm) for a metal-solution interface. Unfortunately, the information carried both by the former and the latter is identical, to a considerable extent. Indeed, it is known from thermodynamics that the electrode charge \({{Q}_{e}}={d\sigma }/{d\psi _{m}^{2}}\;\) and, hence, the differential capacity of EDL \({{c}_{m-s}}={d{{Q}_{e}}}/{d{{\psi }_{m}}}\;={{{d}^{2}}\sigma }/{d\psi _{m}^{2}}\;\). Thus, using an electrocapillary curve measured with a sufficient accuracy, we can reconstruct a differential capacity curve Cm-s(ψm). The in-verse procedure is, however, impossible, since